It is a requirement of the mine safety laws that in most instances temporary roof supports must be positioned before a miner can enter the space below an unbolted or otherwise permanently supported roof. Until recenty, it has been neccessary for miners to enter under the unsupported roof to place temporary support jacks. Roof bolting devices have been proposed in which a canopy generally positioned over the operator may be raised to engage the roof. It has also been proposed to provide a swinging boom type temporary roof support extending from the chassis of the roof bolting machine. The boom is connected to the chassis for angular movement about more than one axis. The end of the boom supports one small area directly surrounding the point where the boom engages the mine roof. A considerable moment is placed upon the vehicle if roof collapse loads the swinging boom. Prior art temporary roof supports are disclosed in U.S. Pat. Nos. 4,079,792; 3,893,520; and 3,768,574, for example.
It is an advantage according to the applicants' invention to provide a temporary roof support carried by the chassis of a roof drilling and bolting machine or the like on a boom extending forwardly of the chassis. The boom is pivotally secured to the chassis for rotation about one axis only. An extensible standard pivotally secured to the opposite end of the boom is vertically positoinable and extensible such that load is not transferred to the vehicle by the boom after the extensible standard is emplaced.